Not @Slack, but slack time, time when you aren’t buried on a particular project.
In the book, The Phoenix Project, the Brent character is the jack of all trades, the one that everyone goes to to fix and solve problems. He gets tasked with important projects and work, which means he’s always busy. I’ve been in this position, and a few of you are likely depended upon like this at your job.
Slowly, the other characters start to realize that if Brent is fire fighting, or he’s on a long project, then he can’t get other things done. He likes and wants to complete work, something most of us do, which means that unless he has windows to tackle new work, he never gets to new work.
It’s important to break work down and work in small windows. It’s also important to ahve some free time available for anything that comes up. That way if there is something important, you can tackle it without subjecting that item to a long delay. If you also find that some work can be handled by others or isn’t important, you have a break to switch to something else and leave the less important project behind.
This comes from flow of work and theory of constraints, outlined in The Goal, from manufacturing. Ensuring that some resource is always busy doesn’t make sense from an flow standpoint. This is discussed in the book, Slack, as well.
If you haven’t read The Phoenix Project, it’s a quick and easy read. A little silly, somewhat exaggerated, but it makes a point that’s worth making in how we work in technology.